• YAKHAK HOEJI
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• v.36 no.2
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• pp.159-166
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• 1992

A neoglycolipid, N-stearyl lactobionamide(N-SLBA) was synthesized and the incorporation of the neoglycolipid into liposomes was achieved in order to prepare neo-galactosylated liposome as potential drug carrier for active targeting to galactose receptor existing cell and tissue. N-SLBA was synthesized by the covalent linkage between carboxyl group of lactobionic acid and amino group of stearylamine(SA). The yield of N-SLBA was about 52.3%. It was identified with $1650\;cm^{-1}$ in IR chart, 7.5 ppm in NMR spectra, $61^{\circ}C$ endothermic peak in DSC heating curve. Surface-modified large unilamellar vesicle with galactose(N-SLBA-LUV) could be prepared with N-SLBA by reverse evaporation method. N-SLBA-LUV was identified by TEM and measuring of membrane function. The maximum amount of N-SLBA incorporated into liposome is up to about 15 mol%. Compared with control liposome (SA-LUV), N-SLBA-LUV showed lower encapsulation efficiency of MTX. It might due to the loss of positive surface charge of stearylamine. N-SLBA-LUV was similar to SA-LUV in aspect of osmotic behavior. N-SLBA-LUV prepared with N-SLBA would be expected to be a good carrier for active targeting to galactose receptor existing cell and tissue.

• Molecules and Cells
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• v.46 no.4
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• pp.191-199
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• 2023

The Golgi apparatus modifies and transports secretory and membrane proteins. In some instances, the production of secretory and membrane proteins exceeds the capacity of the Golgi apparatus, including vesicle trafficking and the post-translational modification of macromolecules. These proteins are not modified or delivered appropriately due to the insufficiency in the Golgi function. These conditions disturb Golgi homeostasis and induce a cellular condition known as Golgi stress, causing cells to activate the 'Golgi stress response,' which is a homeostatic process to increase the capacity of the Golgi based on cellular requirements. Since the Golgi functions are diverse, several response pathways involving TFE3, HSP47, CREB3, proteoglycan, mucin, MAPK/ETS, and PERK regulate the capacity of each Golgi function separately. Understanding the Golgi stress response is crucial for revealing the mechanisms underlying Golgi dynamics and its effect on human health because many signaling molecules are related to diseases, ranging from viral infections to fatal neurodegenerative diseases. Therefore, it is valuable to summarize and investigate the mechanisms underlying Golgi stress response in disease pathogenesis, as they may contribute to developing novel therapeutic strategies. In this review, we investigate the perturbations and stress signaling of the Golgi, as well as the therapeutic potentials of new strategies for treating Golgi stress-associated diseases.

• Applied Chemistry for Engineering
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• v.35 no.3
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• pp.230-238
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• 2024

In the present work, the interaction of lipid-based zwitterionic surfactant CDP-W with the vesicle membrane of phospholipids was investigated. For this purpose, interfacial properties such as critical micelle concentration (CMC) and surface tension were measured for the zwitterionic surfactant CDP-W and lecithin S100-3. The zeta potential of 1 wt% aqueous surfactant solutions was also measured as a function of pH to determine the iso-electric point of CDP-W surfactant, where the characteristic of CDP-W surfactant changes from a cationic surfactant to an anionic surfactant. Based on the iso-electric point measurement of CDP-W surfactant, the effects of pH change and CDP-W addition on the stability of S100-3 liposome systems were studied, such as average particle size, polydispersity index (PDI), and zeta potential. The effect of CDP-W on the fluidity characteristics of liposome membranes such as fluorescence anisotropy ratio, deformability, and melting point was investigated at pH 6 where the most stable liposomes were prepared to understand the effect of the fluidity of the liposome membrane on the encapsulation efficiency of active materials and the stability of liposome systems.

• Animal cells and systems
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• v.5 no.1
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• pp.45-50
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• 2001

Rana ovarian follicles consist of oocyte, vitelline envelope, granulosa cells, and theca/epithelial layer. Using scanning electron microscopy, the surface structure of each follicular component was investigated. Changes in oocyte surface during oocyte maturation were also examined. Theca/epithelial layer was almost transparent and some blood vessels and granulosa cells were observed underneath in intact follicle. The number of granulosa cells was estimated to be 6700-7200 per oocyte. The granulosa cells partially overlapped each other and their microvilli penetrated the vitelline membrane via holes present in the vitelline envelope and seemed to be linked to oocyte microvilli. After removal of the vitelline envelope by microforcep, oocyte microvilli were observed on the surface of the devitellined oocyte. The oocyte microvilli formed partial clusters on the surface of white spot area which appears iust before germinal vesicle breakdown (GVBD), whereas they were evenly distributed in other areas. The microvilli became shorter and less dense with oocyte maturation. The lengths of oocyte microvilli in the immature and mature oocyte were 1.5 $\mu$m and 0.6 $\mu$m, respectively. The present study suggests a fundamental structural change occurring on the oocyte surface during maturation.

• Bulletin of the Korean Chemical Society
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• v.23 no.11
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• pp.1616-1622
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• 2002

If the surfaces of vesicles are chemically modified so that they can be dispersed in organic solvents, the application of vesicular colloids may be expanded. A polymerizable surfactant (BDAC) and nonpolymerizable bipolar surfactant (BPAS) were synthesized in multi-steps. Large vesicles composed of BDAC and BPAS with embedded a cross-linking agent (divinylbenzene) underwent a radical polymerization. BPAS was extracted out using methanol (skeletonization). The headgroup of BDAC was cleaved off via hydrolysis in an acidic condition to yield vesicles where surfaces were covered with -COOH groups. There was no significant change in the overall shape. The skeletonized vesicles appear to have many holes with diameters up to about 25 nm. The holes retained even after hydrolysis. The hydrolyzed vesicles were not dispersed in water and most organic solvents such as tetrahydrofuran and chloroform, but dispersed in methanol.

• Preventive Nutrition and Food Science
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• v.16 no.2
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• pp.135-141
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• 2011

Inhibition of intestinal glucose uptake is beneficial in reducing the blood glucose level for diabetes. To search for an effective intestinal glucose uptake inhibitor from natural sources, 70 native edible plants, fruits and vegetables were screened using Caco-2 cells and fluorescent D-glucose analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose (2-NBDG). A compound that was able to inhibit glucose uptake was isolated from methanol extract of Punica granatum L. and called PG-1a. PG-1a appears to be a phthalic acid-diisononyl ester- like compound (PDE) with molecular weight of 418. The inhibitory effect of PG-1a on intestinal glucose uptake was dose-dependent with 89% inhibition at $100\;{\mu}g$/mL. Furthermore, the intestinal glucose uptake inhibitory effect of PG-1a was 1.2-fold higher than phlorizin, a well known glucose uptake inhibitor. This study suggests that PG-1a could play a role in controlling the dietary glucose absorption, and that PG-1a can effectively improve the diabetic condition, and may be used as an optional therapeutic and preventive agent.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1069-1075
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• 2004

In an attempt to evaluate the function of MAP kinase in porcine oocytes and to develop a method of the assessment of its activity, myelin basic protein (MBP) was used as a substrate to detect the MAP kinase activity of porcine oocytes which had undergone maturation in vitro. The existence of MAP kinase and MAP kinase kinase (MAPKK) was verified in immature porcine germinal vesicle (GV) oocytes at 0 h culture via Western blotting. Porcine oocytes exhibited a low level of MAP kinase activity during the first 20 h of culture, which increased at 25 h, during which time a breakdown in the nuclear membrane occurred. Significantly higher increases (p<0.05) of MAP kinase activity were detected at 30 h of culture. Using the gel phosphorylation method, MBP was phosphorylated at two positions corresponding to mammalian MAP kinase-extracellular signal-regulated kinase (ERK 1) (44 kDa) and ERK 2 (42 kDa). The absolute levels of those proteins did not increase during 40 h of culture, suggesting that the detected increase in MAP kinase activity was the result of phosphorylation rather than changes in the total amount of protein. MAPKK and MAP kinase were dephosphorylated in first-stage (MI) meiotic oocytes by the addition of cycloheximide, a protein synthesis inhibitor. These results of this study indicate that the MAP kinase cascade does exists in porcine oocytes and that its activation leads to oocyte maturation.

• The Korean Journal of Zoology
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• v.26 no.2
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• pp.107-123
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• 1983

The globus pallidus of normal cats were prepared for electron microscopic study following perfusion with a mixture of 1% paraformaldehyde and 1% glutaraldehyde solution. Neurons of two size categories were identified in 1 $\\mu$m araldite sections and their ultrastructural characteristics were studied in adjacent thin section. 1. Large neurons ($30 \\mum \\times 45 \\mum$ in diameter) had extensive areas of rough surfaced endoplasmic reticulm, abundant perinuclear Golgi complex, numerous mitochondria and lipofusin granule, and had a large spherical nucleus with shallow indentation of nuclear manbrane. Small neurons ($17 \\mum \\times 27 \\mum$ in diameter) had poorly rough surfaced endoplasmic reticulum, moderate number of mitochondria and randomly distributed Golgi complex. The nuclear envelope of this cell frequently showed multiple deep invagination. 2. Three types of axo-somatic synapses were identified on the basis of the size and shape of vesicle in the axon terminal and the symmetrical or asymmetrical thickening at the synaptic site. Type I synaptic terminal shows an even distribution of round and oval synaptic vesicles, and has a symmetrical synaptic thickening. Type II axon terminals reveal mostly round and pleomorphic vesicles and a few vesicles were localized near the presynaptic membrane in pale axoplasm and its synaptic thickening were symmetric. Type III axon terminals contain round vesicles, which were aggregated in the axoplasm, and has a asymmetrical synaptic thickening. 3. The majority of axo-somatic contact with the large and small neurons were type I, and type II and III synapes were rare.

• BMB Reports
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• v.37 no.4
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• pp.460-465
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• 2004

A 16-residue polypeptide model with the sequence acetyl-YALSLAATLLKEAASL-OH was derived by rational de novo peptide design. The designed sequence consists of amino acid residues with high propensity to adopt an alpha helical conformation, and sequential order was arranged to produce an amphipathic surface. The designed sequence was chemically synthesized using a solid-phase method and the polypeptide was purified by reverse-phase liquid chromatography. Molecular mass analysis by electro-spray ionization mass spectroscopy confirmed the correct designed sequence. Structural characterization by circular dichroism spectroscopy demonstrated that the peptide adopts the expected alpha helical conformation in 50% acetonitrile solution. Liposome binding assay using Small Unilamellar Vesicle (SUV) showed a marked release of entrapped glucose by interaction between the lipid membrane and the tested peptide. The channel-forming activity of the peptide was revealed by a planar lipid bilayer experiment. An analysis of the conducting current at various applied potentials suggested that the peptide forms a cationic ion channel with an intrinsic conductance of 188 pS. These results demonstrate that a simple rational de novo design can be successfully employed to create short peptides with desired structures and functions.

• Applied Microscopy
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• v.5 no.1
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• pp.31-43
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• 1975

These studies were carried out to detect the presence of infected virus- like particles and also were observed the ultrastructures of Aspergillus ochraseus isolated from kokja and Korean ginseng. The results of ultrastructures of Aspergillus ochraseus are summarized as follows: 1. In fungal cells, nuclei were enclosed by a irregular double membrane and nucleoli in the nucleus. 2. In cytoplasm, mitochondria, rough endoplasmic reticulum with ribosomes and glycogen were scattering distributed and many lomasomes also observed. 3. The osmiophilic bodies of fungal cells existed in the vesicles. 4. The cell walls were composed of a low electron dense materials. 5, Conidia cell walls were extremely thick and possessed the high electron density of outer coat. The virus-like particles were observed in the hyphae of Penicillium chrysogenum Q-176. These virus-like particles measured $350{\AA}$ in diameter. But strains of Aspergillus ochraseus, showing some vesicle particles were also observed about $800{\AA}$ in diameter in the central region of young fungal hyphae. Based on the results of these experiments, it can not be determined virus particles or not. The further studies to determination of virus particles will be proceeded by the chemical, physical and biological assay methods.